Chevron Shipping, Wärtsilä Convert LNG Carriers to Spark Gas Operation

Wärtsilä, in collaboration with Chevron Shipping Co., will convert one engine on six Chevron Transport LNG carriers from dual-fuel (DF) to spark gas (SG) operation, reducing greenhouse gas emissions by lowering methane slip. LNG, when fired as fuel, generates small amounts of non-combustible methane that may escape into the atmosphere—this is called methane slip. Methane has a shorter atmospheric lifespan than CO₂, but traps approximately 25 – 30 times more heat over a 100-year period.

“Chevron Shipping aims to reduce the methane emissions intensity of our LNG fleet in support of a lower carbon future,” says Barbara Pickering, President of Chevron Shipping. “We are pleased to collaborate with Wärtsilä in this industry first. This demonstrates steps we are taking to help reduce the carbon intensity of marine transportation."

Wärtsilä’s 50DF to SG conversion project will modify the in-service engines to use spark ignition versus diesel pilot fuel for combustion. SG operation enables an optimized combustion process, mitigating methane slip and improving overall efficiency. The first two vessel orders were booked by Wärtsilä in Q3 2024.

31SG marine spark gas engine; Image Credits: Wartsila

“This project represents a notable step forward on the road to advancing lower carbon fleets,” said Roger Holm, President of Wärtsilä Marine & Executive Vice President at Wärtsilä Corp. “Wärtsilä has an extensive track-record in reducing methane slip from LNG-fueled engines, not only as newbuild solutions, but also through retrofitting existing installations.”

Other Chevron News

In early September, Chevron began water injection operations to increase oil and natural gas recovery at its Jack/St. Malo and Tahiti deepwater facilities in the U.S. Gulf of Mexico. The company achieved first water injection in the St. Malo field—a waterflood project in the deepwater Wilcox trend. The project was delivered under budget, adding water injection facilities, two new production wells, and two new injection wells. It is projected to add approximately 175 million barrels of oil equivalent to St. Malo field’s gross ultimate recovery.

At the Tahiti location, Chevron started injecting water into its first Gulf producer-to-injector conversion wells. The company installed a new water injection manifold and 20,000 feet of flexible water injection flowline. Chevron will study advanced drilling, completion, and production technologies to deploy during future development phases at Tahiti and Jack/St. Malo, with the goal to further increase oil and natural gas recovery from these sites.

And, in August, Chevron started oil and natural gas production at its deepwater asset in the U.S. Gulf of Mexico—the Anchor project. The Anchor—a semi-submersible FPU—features a design capacity of 75,000 gross barrels of oil per day and 28 million gross cubic feet of natural gas per day. The site has reservoir depths up to 34,000 feet below sea-level, and production is aided by high-pressure technology rated up to 20,000 psi.

Development includes seven subsea wells connected to the Anchor FPU, located in the Green Canyon approximately 140 miles offshore Louisiana, in water depths of about 5,000 feet. It is designed as an all-electric facility with electric motors and electronic controls to minimize carbon emissions. In addition, the FPU uses waste heat and vapor recovery units and existing pipelines to transport oil and natural gas to U.S. Gulf Coast markets.